Yo
Toms did an article a while back on this.
Was quite interesting.
In most benchmarks there was no difference at all. That was mostly games, though. I think in certain apps, ones working with large files, such as adobe premiere, you might notice a difference.
What I did see a difference in though, was memory speed. I had DDR2-533 in my machine. Then I sold and got DDR2-666 (I know it's 667, but this looks better :twisted: )In 3DMark2005, I could actually see a surprizing difference.
True also that 64 bit aint too rosy yet. I had lots of troubles, so I'm running normal xp pro again.